Well our TV broke down at the weekend and so I decided for the first time to make use of the TV and Movies features of the iTunes store. I bought a few TV episodes and they play back fine, I downloaded some free stuff and that played back fine. I rented 3 movies and whenever I play them all I get is a grey screen and no audio.

Searching the web shows loads of people with the same problem and no solution! Apple have one page that basically says upgrade QuickTime and iTunes to the latest versions, I have the latest versions and have re-installed them both anyway and to try deleting the sc info folder which I believe is where you authorization info is stored. Tried all of that and still I get nothin but a grey screen.